NewLink Genetics Corp. announced it has rejected an unsolicited acquisition proposal from Evercel Inc., after determining the offer is not in the best interests of its shareholders. The Ames-based company said Evercel’s offer made on Nov. 5 is not, and could not be reasonably expected to lead to, a superior offer to the definite merger agreement it entered with Lumos Pharma Inc. in September. Under that agreement, NewLink could negotiate with a competing proposal if it met that “superior offer” threshold. NewLink said it remains focused on completing the proposed merger with Lumos Pharma and the subsequent development of Lumos’ lead drug candidate, a potential oral therapy for pediatric growth hormone deficiency.